What is the most successful x-rated movie of all time?

The most successful pornographic movie of all time is "Deep Throat." It only cost $50,000 to make but did a business of more than $100 million.

Deep Throat was made in 1972 starring American porn star Linda Lovelace. The film was written and directed by Gerard Damiano (listed in the credits as "Jerry Gerard") and produced by Louis Peraino (as "Lou Perry") and starring Linda Lovelace (the pseudonym of Linda Susan Boreman).

It was also one of the first pornographic films to feature a plot, character development and relatively high production standard. Deep Throat earned mainstream attention and launched the "porn chic" trend despite the film being banned in some regions and the subject of obscenity trials.